Pharmacotherapeutic outcomes in atypical odontalgia: determinants of pain relief

Reappraising the psychosomatic approach in the study of "chronic orofacial pain": looking for the essential nature of these intractable conditions

As burning mouth syndrome (BMS) and atypical odontalgia (AO) continue to remain complex in terms of pathophysiology and lack explicit treatment protocol, clinicians are left searching for appropriate solutions. Oversimplification solves nothing about what bothers us in clinical situations with BMS or AO. It is important to treat a complicated phenomenon as complex. We should keep careful observations and fact-finding based on a pragmatic approach toward drug selection and prescription with regular follow-up. We also need to assess the long-term prognosis of treatment with a meticulous selection of sample size and characteristics. Further investigation of BMS and AO from a psychosomatic perspective has the potential to provide new insight into the interface between brain function and "chronic orofacial pain."

Treatment of Persistent Idiopathic Dentoalveolar Pain with Venlafaxine: A Multicentric Retrospective Study on Its Effectiveness and Safety

Purpose

To determine the effectiveness and safety of venlafaxine in treating persistent idiopathic dentoalveolar pain (PIDP).

Patients and Methods

A retrospective analysis was conducted on a cohort comprising 129 patients with a definite diagnosis of PIDP, who were treated with venlafaxine between May 2020 and December 2022 at three different institutions. Baseline characteristics were statistically described, and visual analog scale (VAS) scores before and during treatment were collected. The percentage of pain relief was calculated. Differences in baseline characteristics between responsive and unresponsive patients were evaluated. Additionally, side effects experienced during treatment were also summarized.

Results

Among the included patients, 4 suffered immediate side effects following the initial dose of venlafaxine and the treatment was discontinued. 104 (80.6%) patients achieved pain relief. VAS scores of responsive patients at weeks 2, and months 1, 2, and 3 were significantly lower than baseline (p<0.001). Duration of pain was the only factor related to responsiveness (Wilcoxon rank sum test p<0.001, logistic regression p=0.001). 64 patients (49.6%) suffered from mild side effects. No serious side effects were observed during the study.

Conclusion

Venlafaxine is potentially effective and safe in the management of PIDP. Early application of venlafaxine following the diagnoses of PIDP can result in a higher possibility of pain relief.

Diagnosis and treatment of intractable idiopathic orofacial pain with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) has been reported to be associated with primary chronic pain syndromes, such as fibromyalgia, migraine, and chronic low back pain. Although idiopathic orofacial pain (IOP) is classified as burning mouth syndrome or persistent idiopathic facial or dentoalveolar pain and as a primary chronic pain, the association between IOP and ADHD has not been investigated. This retrospective cohort study investigated the severity of ADHD symptoms measured using the ADHD scale and the effects of treatment using ADHD drugs and the dopamine system stabilizer aripiprazole. The participants were 25 consecutive patients with refractory IOP referred to a psychiatrist and diagnosed with coexisting ADHD according to the Diagnostic and Statistical Manual of Mental Disorders-5. The ADHD scale scores were higher in patients with intractable IOP than those in the general population. Pharmacotherapy used in this study led to clinically significant improvements in pain, anxiety/depression, and pain catastrophizing. Intractable IOP and ADHD were shown to be associated. In the future, screening and pharmacotherapy for ADHD should be considered in the treatment of intractable IOP.

Post-traumatic Trigeminal Neuropathy Associated With Endodontic Therapy: A Systematic Review

A painful or non-painful trigeminal nerve lesion brought on by trauma that exhibits symptoms and/or clinical evidence of trigeminal nerve dysfunction is known as painful post-traumatic trigeminal neuropathy (PTTN). In relation to this, the term post-traumatic persistent dentoalveolar pain (PDAP) is an idiopathic condition of chronic neuropathic origin that manifests as a diagnostic challenge for dental practitioners. Neuropathic pain is defined by the International Association for the Study of Pain (IASP) as "pain initiated or caused by a primary lesion or dysfunction in the nervous system." PDAP is located primarily in the teeth and jaws. This study systematically reviews how likely it is to get painful PTTN if the patient received endodontic therapy and the duration between doing root canal therapy (RCT) and getting PTTN. A systematic review was carried out using key search terms from PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) with English as the only permitted language. There were strict inclusion requirements. The 10 articles that were included showed a prevalence of an endodontic procedure anywhere from three to 48 months following post-endodontic treatment, and it mainly affects females in their mid-40s with no variation regarding the areas, whether it is in the maxilla or mandible. The lack of information about the association between RCT and PTTN led practitioners to make wrong diagnoses, which made the patient unwilling to seek further help. So, in this review, we identified some visible characteristics that can help in that process.

Outcomes and Predictors of Response of Duloxetine for the Treatment of Persistent Idiopathic Dentoalveolar Pain: A Retrospective Multicenter Observational Study

Background

Duloxetine has been reported to significantly relieve the pain of persistent idiopathic dentoalveolar pain (PIDP); however, the number of studies available is scarce and no study has identified the predictors of response of duloxetine for the treatment of PIDP.

Objective

To report the efficacy, safety, and identification of positive predictors of duloxetine for PIDP patients through a retrospective multicenter observational study.

Methods

We retrospectively reviewed the clinical database of PIDP patients who were prescribed duloxetine at 3 hospitals between January 2018 and November 2021. Demographic and pain-related baseline data, efficacy of patients after 3 months of medication by visual analog scale (VAS) scores for pain and adverse events were extracted and analyzed. The predictors of pain-relieving effect of duloxetine were identified by logistic regression analysis.

Results

A total of 135 patients were included in this study. Side effects occurred immediately after taking duloxetine in 24 (17.8%) patients, and the treatment with duloxetine was discontinued on 13 of them because they could not tolerate the side effects. Other 11 (8.1%) patients gradually tolerated the side effects within 2 weeks. Ninety-four out of 122 (77.0%) patients obtained pain relief with VAS significantly decreased (p < 0.01) and the other 28 (23.0%) patients stopped taking the drug because of weak efficacy. Binary logistic regression analysis showed that short disease duration (OR = 1.017, 95% CI = 1.004–1.030, P = 0.012) was an independent predictor of the positive response of duloxetine.

Conclusion

This study confirmed that duloxetine can significantly improve chronic pain of PIDP patients, and the safety was tolerable. Patients with shorter disease duration had more benefit from duloxetine.

Limitations

This is a retrospective observational study. Long-term efficacy and safety of duloxetine in the treatment of PIDP patients were not evaluated.

Pharmacological Approach to Atypical Odontalgia Patients: A Systematic Review of Case Reports

Background:

Atypical odontalgia (AO) is a poorly understood condition of orofacial pain and is often misdiagnosed. The pharmacological approach varies from case to case. This may be due to the differences in etiology, clinical symptoms, as well as comorbidities in each patient.

Objective:

This systematic review aimed at identifying and comprehending the adequate pharmacological approaches in AO management.

Methods:

In this systematic review, case reports that used pharmacological approach(es) as part of the AO management in the last 10 years (2010 to 2020) were reviewed using the PRISMA analysis guidelines. Initial screening was performed using keywords and inclusion criteria in several databases. Subsequently, further screening was carried out by checking for any duplication, followed by an assessment of the title and abstract and the entire content of the case report. All three authors were independently involved in studies selection based on the inclusion criteria, data extraction, and bias assessment.

Results:

Five hundred and ninety-five articles were identified from the initial search. The final result consisted of eleven case reports reviewed in this study. The use of antidepressants in AO management was reported in eight cases, anticonvulsants in five cases, antipsychotic in two cases, opioid analgesics in two cases, and topical analgesics in two cases.

Conclusion:

Based on this systematic review, various pharmacological agents showed adequate results as AO management. Antidepressants seemed to be the most effective ones (PROSPERO registration ID: CRD42021245918).

Case Report: Auditory Hallucination Induced by Amitriptyline for the Treatment of Atypical Odontalgia

Auditory hallucination is usually associated with psychiatric diseases and organic brain illness. It was rarely found as adverse events of antidepressants. Amitriptyline is considered as one of the first line medications for the psychopharmacotherapy of chronic pain including atypical odontalgia (AO) which shows chronic tooth pain without corresponding abnormalities. Anticholinergic adverse events induced by amitriptyline are usually bearable and not critical since the prescription dose is very low for the patients with AO. This is a first case report about the AO patients who showed auditory hallucination by the low dose of amitriptyline. A 43-years-old female, housewife, complained chronic toothache following dental procedures and was diagnosed as AO. Amitriptyline was initially prescribed 25 mg and gradually increased up to 60 mg with the improvement of AO symptoms in 7 months. Although the temporary recurrence was observed following to the retreatment of prosthodontic dental procedures, it improved in a few weeks. Therefore, the dose of amitriptyline was decreased, and the continuation dose was set 30 mg. In 24 months, the AO symptoms were very much improved; however, she reported that she had been heard the voices at midnight for a year. The voices were neighborhoods' and talking about the noise troubles she had claimed before. She had not realized that the voices were auditory hallucination since they were heard only at midnight infrequent and not bothering her daily life. At the time she reported auditory hallucination, she worried whether organic brain diseases are hiding because the frequency of voices was increased and sometimes occurred in daytime. The adverse event of amitriptyline was suspected since she had never had psychotic symptoms before. Amitriptyline was decreased and continued with the dose of 25 mg. Magnetic resonance imaging and psychiatric consultation revealed no abnormality of brain and in psychiatric aspects. After final prosthodontic treatment, the amitriptyline was discontinued in 30 months. Two months after the discontinuation, auditory hallucination was almost disappeared with no recurrence of AO. The present case report suggests that amitriptyline has possibility to induce auditory hallucination even in conventional dose throughout the treatment of chronic pain including AO.

Differences in the Clinical Characteristics of Persistent Idiopathic Facial Pain (Atypical Odontalgia) Patients with or Without Neurovascular Compression of the Trigeminal Nerve

Background

Persistent idiopathic facial pain (PIFP) is the unexplained pain along the territory of the trigeminal nerve, including nonorganic tooth pain called atypical odontalgia (AO). Though PIFP is debilitating to patients’ livelihood and well-being, its pathophysiology remains poorly understood. Although neurovascular compression (NVC) of the trigeminal nerve is known to be associated with trigeminal neuralgia (TN), the relationship between NVC and other orofacial pains has not been fully elucidated.

Methods

In this study, we investigated the differences in the characteristics of PIFP (primarily AO) patients in the presence or absence of NVC. A retrospective analysis was performed on data from 121 consecutive patients who had been diagnosed with unilateral PIFP according to the criteria of the International Classification of Headache Disorders (ICHD)–3 and underwent magnetic resonance imaging scans of the head.

Results

In the group without NVC, characteristic findings were significant for psychiatric morbidity, somatization, and pain disability, when compared with the group with NVC. Furthermore, the group without NVC exhibited significant headache, noncardiac chest pain, shortness of breath, and pain catastrophizing.

Conclusions

These results suggest that PIFP patients can be divided into two groups: one consistent with a neuropathic pain phenotype when NVC is present and a functional somatic symptom phenotype when presenting without NVC. Our findings may enable a more precise understanding of pathophysiology of PIFP and lead to better treatment strategies.